Hi There, Scoop!
I soak my neb and Aerobika parts in warm soapy water (I use Dawn) after every use (2x a day). About 2 or 3x a week, after soaking the parts, I pop them into a Medela Quick steam bag along with 2 ounces of distilled water & nuke them for 3 minutes. There are 20 numbers on the back of the steamer package that you check off after each use. I toss out the bag once I hit #20. Thus far, I have never exceeded the recommended use. Additionally, after soaking in dawn, I then will soak the parts in a 1:1 ratio of water to white vinegar about once a week to demineralize things. I don't know if this is really necessary but I figure it can't hurt.